The generation of pulling force is a basic operation of physical work. Generally, there has been a trade off between the force which may be applied to a pulling operation, and the portability and flexibility of the machine applied to perform the pulling. For example, machines have been developed which are capable of exerting very high pulling forces on a rope or cable. However, these machines tend to be heavy and difficult to transport. Pulling machines also tend to be specialized to particular applications.
U.S. Pat. No. 5,984,273 decribes a pulling apparatus wherein a right-angle drill may be mounted upon a spindle fixed to a length of bar. The right-angle drill may be powered on by toggling a lever switch to depress a trigger of the drill. The drill motor directly drives the spindle around which one or more turns of rope may be made. The force of the drill may be applied to turning the spindle to assist an operator with pulling on the end of the rope. A disadvantage of this apparatus is that the force applied to the spindle is limited to the force which may be directly output by the drill. Furthermore the configuration of the apparatus may be less flexible than desired for a variety of pulling applications.